For producing predetermined breaking points in ceramic components, among others, the laser method is used. For a cost-effective production of individual, components, the components prepared by a laser are processed in multiple-up production and subsequently separated into individual components (one-up production). For this, holes are put in at defined distances into the surface of the components, similar to a perforation. These weak points created therein act as fracture initiation line and reduce the fracture force at selected locations and enable predetermined fracture propagation.
Such a method is used to replace mechanical cutting methods and/or embossing methods and has established itself also in the field of scribing techniques. Here, blind holes are linearly arranged in a row and serve as a predetermined breaking points or fracture initiation lines on components made of brittle materials such as cast metals or ceramics.
It is standard for laser scribing that the holes are put into the material at defined distances.
With this method it is possible that the perforation causes deviations from the predetermined breaking points. Under certain circumstances, asymmetrical fracture propagations can occur. After the separation, a portion of the side faces have a sequence of semicircles and webs (see FIG. 1) and, compared to a mechanically generated, almost smooth notch surface, can be designated as macroscopically rough. Particular attention is paid here to individual webs projecting from the predetermined fracture line.
Hereinafter, a laser scribing line or laser track is to be as an imaginary line which runs through the centers of all holes.